Atec Agilent-E8364A - Manual (Page 30)

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Time-domain (Option 010)
With the time-domain option, data from transmis-
sion or reflection measurements in the frequency
domain are converted to the time domain using
a Fourier transformation technique (chirp Z)
and presented on the display. The time-domain
response shows the measured parameter value
versus time. Markers may also be displayed in
electrical length (or physical length if the relative
propagation velocity is entered).
Time stimulus modes
Two types of time excitation stimulus waveforms
can be simulated during the transformations, a
step and an impulse.
Low-pass step
This stimulus, similar to a traditional time-domain
reflectometer (TDR) stimulus waveform, is used to
measure low-pass devices. The frequency-domain
data should extend from DC (extrapolated value)
to a higher value. The step response is typically
used for reflection measurements only.
Low-pass impulse
This stimulus is also used to measure low-pass
devices. The impulse response can be used for
reflection or transmission measurements.
Bandpass impulse
The bandpass impulse stimulates a pulsed RF signal
(with an impulse envelope) and is used to measure
the time-domain response of band-limited devices.
The start and stop frequencies are selectable by the
user to any values within the limits of the test set
used. Bandpass time-domain responses are useful
for both reflection and transmission measurements.
Time-domain range
The "alias-free" range over which the display is free
of response repetition depends on the frequency span
and the number of points. Range, in nanoseconds,
is determined by: Time-domain range =
(number of points - 1)/frequency span [in GHz]
Range resolution
The time resolution of a time-domain response is
related to range as follows: Range resolution =
time span/(number of points - 1)
Windows
The windowing function can be used to modify
(filter) the frequency-domain data and thereby
reduce over-shoot and ringing in the time-domain
response. Kaiser Beta windows are available.
Gating
The gating function can be used to selectively
remove reflection or transmission time-domain
responses. In converting back to the frequency-
domain the effects of the responses outside the
gate are removed.
Configurable test set (Option 014)
With the configurable test set option, front panel
access loops are provided to the signal path
between the source output and coupler input.
Extended dynamic range configuration
Reverse the signal path in the coupler and bypass
the loss typically associated with the coupled arm.
Change the port 2 switch and coupler jumper con-
figurations to increase the forward measurement
dynamic range. When making full two-port error
corrected measurements, the reverse dynamic
range is degraded by 12 to 15 dB.
High power measurement configuration
Add external power amplifier(s) between the
source output and coupler input to provide up to
+30 dBm of power at the test port(s). Full two-port
error correction measurements possible. When the
DUT output is expected to be greater than +30 dBm,
measure directly at the B input and use an external
fixed or step attenuator to prevent damage to the
receiver. For measurements greater than +30 dBm,
add external components such as couplers,
attenuators, and isolators.
Supplemental performance
Minimum reference channel input level: -35 dBm